I really liked the game! The different variations of 15 are pretty cool! Not gonna say what they are though, for people who may wanna discover them themselves.
You can go straight to the shrine on 12 / speed run - I don't know if that's on purpose or not, but wanted to let you know in case its not!
10 / climbing was really tricky for me. it might have just been me being impatient, though.